Between 1985 and 1996, our Service treated 18 cases of osteochondritis dissecans of the talus in children and adolescents. The lesion is more frequent during childhood than previously thought. Different theories about the etiology of the lesion and the various treatments used are discussed. The outcome was satisfactory in most cases. We consider that, with the exception of type IV Berndt and Harty lesions, preliminary treatment should be conservative, which gave good results in our study. Surgical treatment should be reserved for patients with an unsatisfactory evolution with orthopaedic treatment, with lesions with thick sclerotic edges, or for patients with loose intraarticular fragments.